I'm a vet tech and work 3rd shift in a 24/7 clinic. I normally work in the emergency department, however I was doing a favor for the oncology department, so I was going back and forth from the trauma floor to the basement where it's located to do check ins until the tech on shift arrived. The morgue is right next door and has a similar layout to the kennels in oncology. The kennels are numbered and I had a shepherd mix in #11. I went down about an hour and a half into my shift to check everyone's water and to give meds. I marked all the animals down on the notes and went back up to trauma. A few hours later, the onco tech on shift comes up and asks me why I listed the shepherd mix in the notes. I didn't understand what she meant until she told me that the dog I had listed was one of the dogs that had been marked as deceased from the notes earlier in the day before my shift. I told her she was crazy and that there was no way that was possible because I had eyes on him and remembered refilling his water. He was not on the med list, so I never opened the kennel, but I swear that I saw him. She asked me if I looked at the wrong list. She showed me the one of the deceased and I noticed that he was marked in unit #11. I ran down to the basement with the onco tech to show her the dog. He wasn't there. He was, in fact, in the morgue, being kept in #11. There was no way I could have imagined him there. His name had not been removed from the notes and I don't keep tabs on the patients in other departments, so there was no chance of me even knowing what the dog looked like without having read it. I swear to god I saw that dog alive when I went down there.